Calling pair() works for keyboards since they do a PIN confirmation
afterward and connect later. For headphones we can connect right away.
Calling pair and connect works for both.
BlueZ exposes `Paired` and `Connected` as separate states, but the
Bluetooth page currently conflates them in a few places.
As a result, devices that connect successfully without creating a
pairing bond can fail to appear as connected in COSMIC Settings.
This patch separates those two concepts in the UI/state handling:
- initialize a device as connected from `Connected`, not from
`Connected && Paired`,
- do not let `Paired` updates mutate connection state,
- treat paired or currently connected devices as "known" devices in
the main device list,
- keep `Forget` available only for actually paired devices.
## User-visible effect
This fixes cases such as the DualShock 3, where the controller is
successfully connected but does not show up as connected in the
Bluetooth settings page.
## Notes
This also matches the behavior already used in
`cosmic-applet-bluetooth`, which treats `Connected` and `Paired` as
separate states and reports a device as connected based on
`is_connected()`, not on pairing state.
A follow-up could rename the section/title to better reflect that it
now contains paired-or-connected devices rather than only paired ones.
- [x] I have disclosed use of any AI generated code in my commit
messages.
- [x] I understand these changes in full and will be able to respond to
review comments.
- [x] My change is accurately described in the commit message.
- [x] My contribution is tested and working as described.
- [x] I have read the [Developer Certificate of
Origin](https://developercertificate.org/) and certify my contribution
under its conditions.
